Method of raising fish by use of algal turf

Abstract

A method of producing mature fish using an algal turf as feedstock. The method consists of first growing an algal turf in a growth reservoir while subjecting the turf to an oscillatory water surge; severing the algal turf from its growing surface and transferring the severed algal turf to a second vessel containing young fish. In an optional embodiment, water enriched in oxygen may be removed from the growth reservoir and recycled to the second vessel. Further, at least a portion of the metabolic and respiratory waste products of the fish may be transferred to a growth reservoir containing algal turf.

What is claimed is: 
     
       1. A method of raising fish comprising: (a) transferring algal turf, severed from the growing surface of an algal turf growth reservoir, to a fish rearing tank prior to the algal turf being overgrown by macroalgae;   (B) exposing young fish in the fish rearing tank to the severed algal turf for consumption of at least a portion of the severed algal turf by the fish;   (C) removing water enriched in oxygen from the algal turf growth reservoir and recycling it to the fish rearing tank;   (D) transferring at least a portion of the metabolic and respiratory waste products of the fish to the algal turf growth reservoir; and   (E) repeating steps (A), (B), (C) and (D) until obtaining mature fish in the fish rearing tank; and   (F) harvesting mature fish from the fish rearing tank.   
     
     
       2. The method of claim 1 wherein the severed algal turf is harvested from its growing surface prior to step (A). 
     
     
       3. The method of claim 1 wherein the severed algal turf is harvested from its growing surface subsequent to step (A). 
     
     
       4. The method of claim 1 wherein the algal turf within the algal turf growth reservoir is subjected to an oscillatory water surge. 
     
     
       5. The method of claim 1 wherein the growing surface for the algal turf in the algal turf growth reservoir is a screen. 
     
     
       6. The method of claim 1 wherein the algal turf severed from the growing surface of the algal turf reservoir is of the genera Ulothrix, Cladophora, Enteromorpha, Oscillatoria, Navicula, Anabaena or Nitzschia. 
     
     
       7. A method of raising mature fish comprising: (A) providing a growth reservoir for an algal turf wherein the growing surface for the algal turf is in contact with water and the algal turf is attached to the upper side of the growing surface and creating an oscillatory water surge across the algal turf;   (B) severing at least a portion of the algal turf from the growing surface;   (C) transferring the severed algal turf to a fish rearing tank containing young fish for consumption of at least a portion of the transferred algal turf by the fish;   (D) removing water enriched in oxygen from the growth reservoir and recycling it to the fish rearing tank;   (E) transferring at least a portion of the metabolic and respiratory waste products from the fish rearing tank to the growth reservoir containing the algal turf;   (F) continuously repeating steps (B) through (E) until obtaining mature fish in the fish rearing tank; and   (G) harvesting mature fish from the fish rearing tank.   
     
     
       8. The method of claim 7 wherein the algal turf is harvested from the growing surface prior to its introduction into the fish rearing tank. 
     
     
       9. The method of claim 7 wherein the growing surface for the algal turf is a screen. 
     
     
       10. The method of claim 7 wherein the water removed from the growth reservoir in step (D) is treated with free oxygen prior to its transfer to the fish rearing tank. 
     
     
       11. The method of claim 7 wherein the algal turf of step (A) is produced by introducing algal spores into the growth reservoir, providing a growing surface for said spores and subjecting the growing surface to light. 
     
     
       12. The method of claim 7 wherein the fish is Tilapia. 
     
     
       13. The method of claim 7 wherein the algal turf is of the genera Ulothrix, Cladophora, Enteromorpha, Oscillatoria, Navicula, Anabaena or Nitzschia. 
     
     
       14. A method of producing mature fish which comprises: (A) transferring algal turf from an algal turf growth reservoir to a fish rearing tank;   (B) exposing young fish in the fish rearing tank to the transferred algal turf for consumption of at least a portion of the transferred algae by the fish;   (C) optionally repeating steps (A) and (B) until mature fish are produced;   (D) harvesting mature fish from the fish rearing tank.   
     
     
       15. The method of claim 14 which further comprises, prior to step (D), removing water enriched in oxygen from the algal turf growth reservoir and recycling it to the fish rearing tank. 
     
     
       16. The method of claim 14 which further comprises, prior to step (D), transferring at least a portion of the metabolic and respiratory fish waste products from the fish rearing tank to the algal turf growth reservoir. 
     
     
       17. The method of claim 14 wherein the algae is harvested from its growing surface prior to step (A). 
     
     
       18. The method of claim 14 wherein the algae is harvested from its growing surface subsequent to step (A). 
     
     
       19. The method of claim 14 wherein the algae produced in the algal turf growth reservoir is subjected to an oscillatory water surge. 
     
     
       20. The method of claim 14 wherein the growing surface for the algae in the algal turf growth reservoir is a screen. 
     
     
       21. The method of claim 14 wherein the algal turf is of the genera Ulothrix, Cladophora, Enteromorpha, Oscillatoria, Navicula, Anabaena or Nitzschia. 
     
     
       22. A method of producing mature fish which comprises: (A) providing a growing surface for an algal turf within a growth reservoir, wherein said growing surface is in contact with water;   (B) subjecting said growing surface to light to grow the algal turf on said surface while subjecting the growing surface to water surge motion to promote metabolite cellular-ambient water exchange over it;   (C) severing at least a portion of the algal turf from the growing surface;   (D) transferring at least a portion of the algal turf to a fish rearing tank, containing young fish, for consumption of at least a portion of the algal turf by said fish;   (E) transferring the waste produced by said fish in the fish rearing tank to an algal turf production vessel having a growing surface for algal turf;   (F) subjecting the growing surface of the algal turf production vessel to light to grow said algal turf on said surface;   (G) subjecting the algal turf of the algal turf production vessel to water surge motion to promote metabolite cellular-ambient water exchanges in the vessel;   (H) transferring at least a portion of the algal turf from the algal turf production vessel to the fish rearing tank for consumption of at least a portion of the algal turf by said fish; and   (K) continuously repeating step (E) through step (H) until obtaining mature fish in the fish rearing tank; and   (L) harvesting mature fish from the fish rearing tank.   
     
     
       23. The method of claim 22 wherein at least a portion of the algal turf from the growth reservoir is harvested from its growing surface prior to its introduction into the fish rearing tank. 
     
     
       24. The method of claim 23 wherein at least a portion of the algal turf from the algal turf production vessel is harvested from its growing surface prior to its introduction into the fish rearing tank. 
     
     
       25. The method of claim 22 wherein at least a portion of the algal turf from the algal turf production vessel is harvested from its growing surface prior to its introduction into the fish rearing tank. 
     
     
       26. The method of claim 22 wherein the growing surface for the algal turf in the growth reservoir is a screen. 
     
     
       27. The method of claim 26 wherein the growing surface for the algal turf in the algal turf production vessel is a screen. 
     
     
       28. The method of claim 22 wherein the growing surface for the algal turf in the algal turf production vessel is a screen. 
     
     
       29. The method of claim 22 further comprising, subsequent to step (C) transferring from the growth reservoir water enriched in oxygen to the fish rearing tank. 
     
     
       30. The method of claim 22 further comprising, subsequent to step (G) transferring from the algal turf production vessel water enriched in oxygen to the fish rearing tank. 
     
     
       31. The method of claim 30 further comprising, subsequent to step (G) transferring from the growth reservoir water enriched in oxygen to the fish rearing tank. 
     
     
       32. The method of claim 22 wherein the algal turf transferred to the fish rearing tank in step (D) is of the genera Ulothrix, Cladophora, Enteromorpha, Oscillatoria, Navicula, Anabaena or Nitzschia. 
     
     
       33. The method of claim 22 wherein the fish is Tilapia. 
     
     
       34. A method of producing mature fish which comprises: (a) providing a growing surface for an algal turf within a growth reservoir, wherein said growing surface is in contact with water;   (B) subjecting said growing surface to light to grow the algal turf on said surface;   (C) transferring at least a portion of the water enriched in oxygen from the growth reservoir to a fish rearing tank, containing young fish, for metabolic interchange;   (D) transferring at least a portion of the metabolic and respiratory waste products of the fish to the algal turf growth reservoir;   (E) continuously repeating steps (B) through (D) until mature fish are obtained; and   (F) harvesting mature fish from the fish rearing tank.   
     
     
       35. The method of claim 34 wherein the algal turf within the algal turf growth reservoir is subjected to an oscillatory water surge. 
     
     
       36. The method of claim 34 wherein the growing surface of the algal turf in the algal turf growth reservoir is a screen. 
     
     
       37. The method of claim 34 wherein the water removed from the growth reservoir in step (C) is treated with free oxygen prior to its transfer to the fish rearing tank.